Roof integrated photovoltaic system

ABSTRACT

A roof integrated photovoltaic (RIPV) system has a plurality of solar tiles that are mounted to a roof. The tiles may be mounted using a metal batten and hanger system or some other attachment system. Each tile has an electrical edge junction extending reawardly from its top edge. The edge junction is coextensive with or contains the plane of the solar tile and may be slightly thicker than the solar tile. Sockets on opposed ends of the edge junction receive plugs of electrical cables for interconnecting the array of solar tiles together electrically. The edge junctions provide for a low profile installation that mimics the appearance of a traditional roofing tile such as a slate tile. The slightly thicker edge junctions may raise solar tiles of one course above the surfaces of solar tiles of a next lower course to provide ventilation for the RIPV array and to provide accommodating space for system wiring.

REFERENCE TO RELATED APPLICATION

Priority is hereby claimed to the filing date of U.S. provisional patentapplication 62/574,560 filed on Oct. 19, 2017 and entitled Solar tileSystem.

TECHNICAL FIELD

The invention disclosed herein relates generally to photovoltaic energyproduction and more specifically to a roof integrated photovoltaicsystems having thin low profile solar tiles that mimic a traditionalroofing tile.

BACKGROUND

Roof integrated photovoltaic (RIPV) systems are continually becomingmore available and more affordable. These systems have evolved in recentyears such that many of them no longer present a bulky industrial andunsightly appearance on a roof. The solar tiles or, more appropriatelysolar tiles, of these systems have become increasingly thinner. In fact,some solar tiles are less than half an inch thick and resembletraditional slate or asphalt shingles when installed in courses on aroof. This is good for consumers because modern RIPV systems canactually be architecturally pleasing and desirable while also producingsustainable electrical energy from sunlight.

As demand for thinner and lower profile solar tiles has grown, a problemhas arisen with the electrical connector systems on solar tiles andsolar tiles that are used to interconnect the solar tiles of a RIPVarray together electrically. More specifically, these connectorstraditionally are on the terminal ends of wires that extend fromjunction boxes mounted to the backs of solar tiles. This limits thethinness of a solar tile assembly to the thickness of the tile itselfplus the thickness of its junction box and/or connectors. A need existsfor an RIPV system wherein the thinness of individual solar tiles is notlimited by the electronic junction boxes or connectors of the tile. Itis to the provision of such a RIPV system that the present invention isprimarily directed.

SUMMARY

Briefly described, an RIPV system is made up of individual solar tilesthat are installable in courses on a roof to produce electrical energywhen exposed to sunlight. In a preferred embodiment, the tiles resembletraditional slate shingles in size and appearance. The tiles may bemounted to a roof using a batten and hanger system such as the TruSlate®system available from GAF of Parsippany, N.J., or some other mountingsystem appropriate for securing the solar tiles to a roof. When somounted, the forward edge of each solar tile in a course overlapsslightly the back edge of a tile or tiles in a next lower course.Rainwater is shed from course to course and eventually directed off theroof at its eves.

Each solar tile of the system is provided with an edge connector or edgejunction with which it is electrically connected to adjacent tiles usingcables. The edge junction serves the function of a junction box on theback of a traditional solar panel in that electrical energy produced bythe solar cells of the tile is directed to the edge junction. Sockets onopposed ends of the edge junction receive plugs of cables thatinterconnect the tiles electrically together. The edge junction is thinand projects reawardly from the back edge of its tile so that it issubstantially coextensive with the solar tile itself or at leastcontains the plane of the solar tile.

It will be recognized that the thinness of each solar tile is notlimited by the thickness of its electrical edge junction because theelectrical junction is mounted on an edge of the solar tile rather thanon its back surface. In one embodiment, the edge junction is slightlythicker than the solar tile itself such that tiles of one course mayrest on the connectors of tiles in a next lower course. As aconsequence, the front edges of tiles in the upper course are heldslightly above the top surfaces of tiles in the lower course. Thisprovides ventilation beneath the solar tiles of the system to helpmaximize the efficiency of the tiles. It also creates a space adjacentthe top edge of each tile to accommodate cables and their plugs.

Thus, an RIPV system is presented in which the individual solar tilescan be thin and may resemble traditional roofing tiles. The tiles aresimple to interconnect with cables during installation, are easy toremove if necessary for replacement or maintenance, provide forventilation beneath the installed tiles, and define an accommodatingspace for cables and their plugs. These and other aspects, features, andadvantages of the RIPV system will be understood better upon review ofthe detailed description set forth below taken in conjunction with theaccompanying drawing figures, which are briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one common batten-and-hanger system known as the TruSlate®system for installation of slate roofing tiles on a roof deck.

FIG. 2 shows two solar tiles according to the present inventionsupported side-by-side by the TruSlate® hanger system of FIG. 1.

FIG. 3 shows a plurality of solar tiles of the present invention mountedon a roof deck along with non-solar tiles to form a roof covering.

FIG. 4 is a right front perspective view of a single solar tileincorporating aspects of the present invention in one form.

FIGS. 4a-4d show possible surface decorations or features that can beapplied to the top surfaces of solar tiles to enhance their appearance.

FIG. 5 is a top plan view of the solar tile of FIG. 4

FIG. 6 is a back elevational view of the solar tile of FIG. 4.

FIG. 7 is a side elevational view of the solar tile of FIG. 4.

FIG. 8 is a close-up view of the back edge of a tile according to thisinvention showing the edge junction extending rearwardly from the backedge of the tile and having cables connected to its ends.

FIGS. 9 and 10 show removal of a solar tile from an installed system oftiles for repair or replacement according to aspects of the invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Reference will now be made in more detail to the drawing figures,wherein like reference numerals refer to like parts throughout theseveral views. The invention is described and depicted herein within thecontext of solar tiles for installation using the TruSlate® metal battenand hanger system available from GAF. This system is described in detailin U.S. Pat. Nos. 8,033,072; 7,454,873; and 7,448,117 and these patentsare hereby incorporated by reference. It will be understood, however,that the invention is not limited to being installed using thisparticular hanger system or any hanger system at all. In fact, anysystem for installing solar tiles on a roof deck may be used such as,for instance, rack systems, frame systems, headlap fasteners, or anyother system. The TruSlate® batten and hanger system is used herein forconvenience and as an example to add clarity and context to thediscussion.

FIG. 1 shows a section of a pitched roof to which a TruSlate® stylebatten and hanger system has been attached for supporting roof tilesaccording to the incorporated U.S. patents. The roof has a roof deck 12covered with a waterproofing underlayment 13. A plurality of metalbattens 14 are attached to the roof deck with screws 17 (FIG. 2) in avertically spaced array. The battens 14 are configured to receive andsecure a plurality of spring steel hangers 16. Each hanger is formedwith a batten attachment feature at its top end and an upwardly archingcrook at its bottom end. For this application, the bottom ends of thehangers are coated in an electrical insulator to avoid electricalcontact between solar tiles and the metal batten system.

FIG. 2 shows two solar tiles 18 according to the invention supported onthe roof deck 12 by the batten and hanger system shown in FIG. 1. Eachsolar tile 18 has an array of solar cells 19 covered with a layer oftransparent or translucent protective material such as tempered glass.The top or upper edges of the solar tiles 18 are captured beneath a pairof hangers 16 depending from the batten 14 directly above the tiles 18.The bottom edges of the solar tiles 12 are nestled in the crooked bottomends of hangers that depend from the batten 14 beneath the solar tiles18 (not visible). In this way, 4 hangers hold the solar tiles securelyto the roof and the spring steel nature of the hangers prevent uplift ofthe tiles in windy conditions. A gap or space 29 is formed between thetop edges of the solar tiles 18 and the batten 14 directly above thesolar tiles to accommodate cables used to interconnect the tileselectrically.

Each solar tile 19 is provided with an edge junction 21 extendingreawardly from the top edge of the tile. The edge junctions 21 containwires that connect electrically to and receive electrical energy fromthe solar cells 19 of the tile. The edge junctions are co-extensive withthe solar tiles or at least contain the plane of the solar tile. In oneembodiment, the edge junctions 21 are a bit thicker than the solar tilesthemselves, which provides for benefits described below. Each edgejunction has opposite ends 26 and 27 (FIG. 6) that form electricalsockets. These sockets are configured to receive a plug 23 on the end ofan electrical cable 22 for electrically interconnecting solar tilestogether in a grid.

The edge junctions 21, plugs 23, and cables 22 are located and containedwithin the accommodating space 29 defined between the tiles 18 and theupper batten 14. The cables 22 extend beneath the hangers 16 that holddown the top edges of the solar tiles. Cables 22 between side-by-sidesolar tiles have some slack as shown in the drawing. The cable 22 at theright end of a course of solar tiles extends upwardly through a gap inthe upper batten to connect electrically to a next higher course ofsolar tiles. The slack in cables 22 connecting side-by-side solar tilesallow for easy removal and replacement of a solar tile in the event of adefective tile, as detailed below.

FIG. 3 shows the roof section covered with solar tiles arranged incourses according to the invention. The illustrated installationcomprises a plurality of solar tiles 18 installed using the batten andhanger system as described. A plurality of non-functional tiles is alsoinstalled on the batten and hanger system. The non-functional tiles aremade to mimic the appearance of the solar tiles on a roof so that theoutline of the solar tile array on a roof is not obvious to an observer.Electrical cables 22 are seen extending between adjacent courses ofsolar tiles to connect the courses together in an electrical grid.

FIG. 4 is a perspective view of a solar tile 18 according to theinvention. Edge junction 21 is seen attached to and extending rearwardlyfrom the top edge of the solar tile. The upper or exposed surface of thesolar tile 18 may be formed with various textures and patterns ifdesired to present the appearance of a traditional shingle such as aslate roofing tile or a cedar shake shingle. For example, and withoutlimitation, the surface may be smooth as shown in FIG. 4a , satin withan embossed texture as shown in FIG. 4b , textured as shown in FIG. 4c ,or satin without texture as shown in FIG. 4 d.

The textures formed in the top surface can be etched, embossed, formedduring manufacture, printed or otherwise applied and can mimic virtuallyany traditional roofing or shingle product. The solar tiles can even becurved or otherwise shaped to mimic, for instance, barrel styleshingles. In fact, completely unique roofing motifs may be created suchas width the satin shingle of FIG. 4 d.

FIG. 5 is a top plan view of a solar tile according to the invention.The tile 18 has embedded solar cells 19 that are electrically coupled toan edge junction 21 along the top edge of the tile. As discussed above,the edge junction has opposed ends 26 that are formed with sockets forreceiving the plugs of electrical cables. The edge junction may beattached to its solar tile with an appropriate adhesive, may have aflange that is connected to the back surface of the tile, or may besecured in any appropriate manner. Any technique of attaching the edgejunction to the tile so that it is coextensive with or contains theplane of the solar tile is within the scope of the invention.

FIG. 6 shows a solar tile according to the invention as seen from thetop edge thereof. In this figure, it can be seen that the edge junctionis slightly thicker than the solar tile itself. The edge junction canthus be said to “contain” the plane of the solar tile in this example.The slightly thicker edge junction provides certain advantages in aninstalled array of solar tiles. For instance, solar tiles in one coursemay rest on the slightly thicker edge junctions of solar tiles in a nextlower course when installed. As a result, the bottom edge portions ofthe tiles in the upper course are raised slightly above the uppersurfaces of the tiles in the next lower course. This, in turn, providesfor ventilation beneath the solar tile array to help maintain thetemperature of the solar tiles within an optimum range for operation anddefines an accommodating space for cables and plugs adjacent the upperedges of the tiles. FIG. 7 is a side edge view of a solar tile 18according to the invention.

FIG. 8 is a close-up view of the top edge of a solar tile 18 mounted tothe batten and hanger system according to the exemplary embodiment ofthe invention. The edge junction 21 is seen extending reawardly from thetop edge of the tile and electrical conductors 28 couple the solar cellsof the tile electrically to the edge junction. End plugs 23 ofelectrical cables 22 are seen attached to the sockets on the opposedends 26 of the edge junction. The edge junctions 21, plugs 23, andcables 22 fit and are contained within the accommodating space 29between the top of the solar tile 18 and the next higher batten 14.Spring steel hangers 16 hold the top edge portion of the solar tile 18down and the insulation coated hooks 15 of the hangers are positioned toreceive the bottom edges of solar tiles in a next higher course.

It is possible for a solar tile within an installed solar array tobecome defective or otherwise need repair or replacement in the future.Unlike many prior art roof integrated solar systems, the illustratedembodiment of the present invention makes this process very simple andeasy to accomplish as shown in FIGS. 9 and 10. In FIG. 9 a worker isseen using a pry tool 31 to lift up slightly the solar tiles 18 of thecourse immediately above the solar tile to be replaced. With the uppersolar tiles lifted, the defective solar tile 18 can be snapped out ofthe crooked ends of hangers that hold its bottom edge in place and sliddown as indicated by arrow 32. This motion is facilitated by thepreviously described slack in cables 22.

As the solar tile slides from beneath the tiles in the next highercourse, its edge junction 21 and cables 22 are exposed to the worker.The worker can then disconnect the plugs 23 from the opposed ends of theedge junction and remove the defective tile. To replace the removedtile, the process is reversed. The plugs 23 of cables 22 are reconnectedto the sockets on the opposed ends of the edge junction of thereplacement tile. The replacement tile is then simply slid upwardlybeneath the solar tiles of the next higher course until it becomescaptured beneath the hangers beneath that course. The bottom edge of thereplacement tile is then snapped into the crooked ends of its hangersand the replacement task is complete.

The invention has been described herein in terms of preferredembodiments and configurations considered by the inventors to representpreferred modes of carrying out the invention. It will be understood bythe skilled artisan, however, that the inventive concepts so embodiedare not limited to the specific examples described above. For example,the solar tiles have been described as being substantially square toresemble a traditional slate-style shingle. The invention can beembodied in other solar tile sizes and designs to mimic, for instance,asphalt shingles or even to present a new and non-traditional aestheticon the roof of a home.

The RIPV system has been illustrated as being installed using a battenand hanger system. However, any installation technique may be usedwithin the scope of the inventive concept. These and other modificationsand additions, both subtle and gross, may well be made to theillustrated and exemplary embodiments herein without departing from thespirit and scope of the invention.

What is claimed is:
 1. A roof integrated photovoltaic (RIPV) system comprising: a plurality of solar tiles arranged in courses on a roof deck, each solar tile having a plurality of solar cells underlying an at least partially transparent protective top layer, each solar tile defining a plane and including an upper edge, a lower edge, and side edges; an edge junction on at least one of the edges of each solar tile, the edge junction being electrically coupled to the plurality of solar cells of the tile and extending away from the solar tile in a direction substantially co-extensive with the plane of the solar tile, the edge junction having first and second ends; a first electrical connector on the edge junction and a second electrical connector on the edge junction; the first and second electrical connectors being configured to be electrically coupled with mating connectors on the ends of corresponding electrical cables for connecting the plurality of solar tiles electrically together; the edge junction, electrical connectors, and electrical cables being disposed within accommodating spaces adjacent the at least one edges of the plurality of solar tiles of the RIPV system.
 2. An RIPV system as claimed in claim 1 wherein the edge junction is on the upper edges of the solar tiles.
 3. An RIPV system as claimed in claim 1 wherein the first electrical connector is on the first end of the edge junction.
 4. An RIPV system as claimed in claim 3 wherein the second electrical connector is on the second end of the edge junction.
 5. An RIPV system as claimed in claim 1 wherein the edge junction has a junction thickness in a direction transverse to the plane of the solar tile, the junction thickness being greater than a thickness of the solar tile.
 6. An RIPV system as claimed in claim 5 wherein the edge junction is on the upper edge of each solar tile and wherein the lower edge of each solar tile rests on the edge junction of a solar tile in a next lower course of solar tiles to define the accommodating space adjacent the upper edges of the solar tiles.
 7. An RIPV system as claimed in claim 1 wherein each solar tile has an exposed surface configured to resemble a traditional roofing tile or shingle.
 8. An RIPV system as claimed in claim 7 wherein the exposed surface is textured.
 9. An RIPV system as claimed in claim 8 wherein the exposed surface is textured to resemble a slate tile.
 10. An RIPV system as claimed in claim 8 wherein the exposed surface is textured to resemble an asphalt shingle.
 11. An RIPV system as claimed in claim 7 wherein the exposed surface is smooth.
 12. An RIPV system as claimed in claim 7 wherein the exposed surface is satin.
 13. An RIPV system as claimed in claim 7 wherein the exposed surface is satin and textured.
 14. An RIPV system as claimed in claim 1 wherein each solar tile is supported by hooks of retainers connected to battens beneath the plurality of solar tiles.
 15. An RIPV system as claimed in claim 1 wherein the plurality of solar tiles are supported by a TruSlate® tile hanging system. 